So you could take it for a long drive, get the fuel as low as you dare, take it really easy though dont get the rpm high and dont use too much throttle. Best place to do this is to get on the highway and just cruise at 100kmh or so. Go until the light comes on to refill, refill with straight 98 no booster, then see if it does it again.
Try and do it so that you turn around and head home halfway through the tank so you're not ages away from home by the time its done. Not sure if that makes sense how i worded it